Reduction of racial and ethnic disparities in cancer incidence, stage of presentation and outcome requires resilient strategies that link medically underserved communities into the continuum of care. Community- based participatory research has the potential to generate such strategies, through processes of collaborative planning, experimentation and discovery. The proposed Queens Library Health Link program is designed to test the efficacy of a comprehensive participatory research approach to reduce disparities by improving use of cancer prevention, screening and treatments interventions. In this project, public library branches provide a base for neighborhood organizing, education, data gathering, planning and implementation of local health promotion experiments and dissemination of results. We will work with 42 of the 63 branch libraries in Queens, each serving its own large, diverse segment of the Queens community. Although we will follow the same process consultation protocol, every community will undertake unique health promotion activities most suited to local priorities, cultures, preferences and opportunities. This project is designed to address the following aims: (1) To determine whether community-based participatory action research (PAR) leads to more effective cancer prevention and control in underserved communities compared to standard, "top-down" programs;(2) To examine how communities build upon and sustain locally-developed initiatives for cancer prevention and control;(3) To compare whether cancer prevention and control strategies developed through PAR are more widely accepted and more efficacious than standard strategies when they are transferred to new communities. This project will be carried out in two phases. In phase 1, we compare health behavioral outcomes of community-tailored strategies to address cancer needs with top-down alternatives. In phase 2, we examine the sustainability and dissemination of tailored strategies. Queens neighborhoods will be randomized to serve as settings for program development or dissemination. Data will be gathered from multiple sources to examine the participatory processes as well as behavioral outcomes at the individual, library and community levels. Core organizations involved in this project comprise a four-way partnership including the Queens Borough Public Library System, the Queens Cancer Center, the American Cancer Society of Queens, and Memorial Sloan-Kettering Cancer Center.